Improvement in key-hole guards



M. SCHOU.

KEY-HOLE GUARD.

Patented June 6, 1876.

Imerz N.FETERSIFNOTO-PTNOGRAPHEH. WASHINGTON. D C.

UNITED STATES PATENT OEEmE MATHIAS soHoU, or ENGLISHTOWN, NEW JERSEY, ASSIGNOR or ONE- HALF HIS RIGHT'TO-THOMAS WEST, or SAME PLACE.

IMPROVEMENT IN KEV-HOLE GUARDS.

Specification forming part of Letters Patent No. 178,334, dated June 6, 1876; application filed May 4, 1876.

To all whom tt may concern:

Be it known that I, MATnIAsj SoHoU, of Englishtown, in the county of Monmouth in the State of New Jersey, have invented certain new and useful Improvements in Key- Hole Guards, of which the following is a full, clear, and exact description, reference being bad to the accompanying drawings, wherein Figure 1 is a perspective view of a lock, with my device attached. Fig. 2, left view, is a front, and right view a rear, elevation of said device. Fig: 3, left view, a side elevation, and right view a front elevation, of the guard in position for insertion in the lock. Fig. 4, a top View, with the lock-casing indicated by the dottedlines; Fig. 5, a side view of a guard provided with means for adjusting it relatively to the thickness or width of the lock and door.

My invention relates to a device for insertion in the key-hole of locks for the purpose of preventing the unlocking of such locks by means of false or other keys, and also'for the purpose of covering said. key-hole, so that it cannot be looked through.

The invention consists in a swingiug guard or plate, carrying a retaining-lug operating in combination with a fixed bit, so that when said lug and bit are inserted in a key-hole of a lock, and the guard locked by a spring Which'it carries, with said bit, the device fills up the key-hole and prevents the insertion of false or other keys, or means for unlocking the lock, and also closes the key-hole, so as to prevent seeing through it.

1n the drawings above referred to, A designates a lock, with my key-hole guard'applied. This guard is composed of a stem, a, of a size sufficient to enter ordinary key-holes of doors. Formed with it is a bit, b, straight on one edge, and having a projecting portion, h, and a recess, m, on the opposite edge. e is a guard or plate, having a hub, c, that rotates on a reduced portion of stem a. d is a lug on hub c, which stands at right angles to the plate 6, when the device is in position in the lock or key-hole, and which lug enters the recess m of bit I), when the device is being inserted in the key-hole. The stem at and guard e are secured together by flattening the end f of Said stem. g is a spring-catch affixed to the order to adapt this guard to fit key-holes of different depths, and in such manner as to have it fit so snugly as to prevent rattling or its being Worked about in the key-hole, I thread the hub, as at k, and fit on it a nut, l,

so that when the device is in the key-hole the' nutl is screwed up to the lock-casing until the lug d and the nut shall be in close contact with opposite faces of the same side of the casing, whereby the device, is held firmly in the key-hole.

In order to apply this guard, the plate 6 is turned up, as in Fig. 3, right view, when the lug d and bit are in line, and can be inserted in the key-hole. back, so as to lock the projection it between the spring 9 and stop j. The end of stem a extends out of the key-hole, so as to prevent the insertion'of a key, and the bit so nearly fills up the key-hole as to make it practically impossible to manipulate the lock with false keys, skeletons, and the like. The guardplate 0 so covers. the key-hole as to prevent looking through it, thus providing a safeguard against inquisitive eyes. 4 When the guard or device is to be removed, the spring 9 is pressed back so as to allow the plate 0 to be swung around, and bring the lug '61 into the recess m, when the device is free to stantially as described.

2. The combination of the recessed bit I) m, stem a, plate 0, hub 0, lug d, spring g, and stops t'j, substantially as and for the purpose specified.

Signed this 1st day of May, 1876.

MATHIAS SGHOU.

Witnesses: v

' THoMAs WEST,

JACOB MUGKELWAINE.

The plate 0 is then swung 

